## Logical Operators

version 6.0

4th Dimension supports two logical operators that work on Boolean expressions: conjunction (AND) and inclusive disjunction (OR). A logical AND returns TRUE if both expressions are TRUE. A logical OR returns TRUE if at least one of the expressions is TRUE.

4th Dimension also provides the Boolean functions True, False, and Not. For more information, see the descriptions of these commands.

The following table shows the logical operators:

 Operation Syntax Returns Expression Value AND Boolean & Boolean Boolean ("A" = "A") & (15 # 3) True ("A" = "B") & (15 # 3) False ("A" = "B") & (15 = 3) False OR Boolean | Boolean Boolean ("A" = "A") | (15 # 3) True ("A" = "B") | (15 # 3) True ("A" = "B") | (15 = 3) False

The following is the truth table for the AND logical operator:

 Expr1 Expr2 Expr1 & Expr2 True True True True False False False True False False False False

The following is the truth table for the OR logical operator:

 Expr1 Expr2 Expr1 | Expr2 True True True True False True False True True False False False

Tip

If you need to calculate the exclusive disjunction between Expr1 and Expr2, evaluate:

`   (Expr1 | Expr2) & Not(Expr1 & Expr2)`